be no/nobody's foolINTELLIGENTto be difficult to trick or deceive, because you have a lot of experience and knowledge about something 不会轻易上当，为人精明，不是傻瓜 Katherine was nobody’s fool when it came to money. 凯瑟琳在钱的问题上一点也不傻。
be no/nobody’s fool• Perhaps he was, she was nobody's fool.
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